Narrative:

Toronto center switched flight over to cle center about 14000' on climb out and cle center cleared flight direct to psb and to climb to FL230. After establishing initial contact with cle center, no other radio communications were received from cle center until flight called cle center climbing through FL200 for FL230 in anticipation of a request for a higher en route altitude. Cle center advised flight, at this time, that the center had lost radio contact with flight for several mins and had to vector another aircraft to avoid a midair collision. Flight advised cle center that the only transmission received was the initial clearance and the #1 radio receiver might be going out, and then switched over to the #2 radio. There was no further discussion with cle center about the other aircraft that was vectored to avoid the midair collision. Flight was operating in VFR conditions with unlimited visibility and observed no other aircraft in the vicinity of our aircraft and neither deviated from the originally assigned route or altitude clearance. After checking the #1 radio with several other centers en route to mia, it was confirmed that the #1 receiver was unreliable and was entered into the aircraft logbook to be replaced. It is very disconcerting to think that our ATC system is so overextended with traffic that lost communications for only a short period of time might result in a midair collision, even on an IFR flight plan.

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Original NASA ASRS Text

Title: LOST COM ON CLIMBING ACR ACFT RESULTS IN CONFLICT.

Narrative: TORONTO CENTER SWITCHED FLT OVER TO CLE CENTER ABOUT 14000' ON CLBOUT AND CLE CENTER CLRED FLT DIRECT TO PSB AND TO CLB TO FL230. AFTER ESTABLISHING INITIAL CONTACT WITH CLE CENTER, NO OTHER RADIO COMS WERE RECEIVED FROM CLE CENTER UNTIL FLT CALLED CLE CENTER CLBING THROUGH FL200 FOR FL230 IN ANTICIPATION OF A REQUEST FOR A HIGHER ENRTE ALT. CLE CENTER ADVISED FLT, AT THIS TIME, THAT THE CENTER HAD LOST RADIO CONTACT WITH FLT FOR SEVERAL MINS AND HAD TO VECTOR ANOTHER ACFT TO AVOID A MIDAIR COLLISION. FLT ADVISED CLE CENTER THAT THE ONLY XMISSION RECEIVED WAS THE INITIAL CLRNC AND THE #1 RADIO RECEIVER MIGHT BE GOING OUT, AND THEN SWITCHED OVER TO THE #2 RADIO. THERE WAS NO FURTHER DISCUSSION WITH CLE CENTER ABOUT THE OTHER ACFT THAT WAS VECTORED TO AVOID THE MIDAIR COLLISION. FLT WAS OPERATING IN VFR CONDITIONS WITH UNLIMITED VIS AND OBSERVED NO OTHER ACFT IN THE VICINITY OF OUR ACFT AND NEITHER DEVIATED FROM THE ORIGINALLY ASSIGNED ROUTE OR ALT CLRNC. AFTER CHKING THE #1 RADIO WITH SEVERAL OTHER CENTERS ENRTE TO MIA, IT WAS CONFIRMED THAT THE #1 RECEIVER WAS UNRELIABLE AND WAS ENTERED INTO THE ACFT LOGBOOK TO BE REPLACED. IT IS VERY DISCONCERTING TO THINK THAT OUR ATC SYS IS SO OVEREXTENDED WITH TFC THAT LOST COMS FOR ONLY A SHORT PERIOD OF TIME MIGHT RESULT IN A MIDAIR COLLISION, EVEN ON AN IFR FLT PLAN.

Data retrieved from NASA's ASRS site as of August 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.